eslint-plugin-compat VS typescript-eslint

I've looked for this in the past. There's not much for this that is totally comprehensive. You might find success with eslint-plugin-compat which will error when using things that aren't supported in your browsers.

eslint-plugin-compat [0] and stylelint-no-unsupported-browser-features [1] can help you know when you're using an unsupported browser feature.

[0] https://github.com/amilajack/eslint-plugin-compat

For now I'm trying to set up [eslint-plugin-compat](https://github.com/amilajack/eslint-plugin-compat) to check it for me, but I'm not sure it works — get 0 errors and 3 polyfills for a test snippet.

Typescript-eslint can assist in this task. This tool helps identify all instances of unsafe any usage. Specifically, all usages of JSON.parse can be found and it can be ensured that the received data's format is checked. More about getting rid of the any type in a codebase can be read in the article Making TypeScript Truly "Strongly Typed".

> Only lint files that have changed? How hard that is?

Quite hard, especially since type-aware rules from e.g. https://typescript-eslint.io/ mean that changing the type of a variable in file A can break your code in file B, even if file B hasn't changed.

The article only touches this: when converting to TypeScript, `any` is useful, but in the end you don't want this type in your codebase - so don't forget to use typescript-eslint [0] and turn on those no-unsafe-* rules which guard against `any` leaking into your code.

[0] https://github.com/typescript-eslint/typescript-eslint

By convention, React components should be named in PascalCase. @typescript-eslint has the config we need, and though we can't specifically target React components, we can target variables (and set some other conventions while we're at it):